From Man to Woman and Back Again: Tiresias, Vat. Myth. I.16

Teresias dum iret per silvam, vidit duos serpents coire, quos cum virga percussisset, in feminam mutatus est. Post octo annos dum videret eos similiter concumbentes et eos rursus percuteret, in pristinam restitutus est naturam. 

--Vat. Myth. I.16

While Tiresias was wandering through the woods, he saw two snakes mating. When he struck them with a stick, he was changed into a woman. Eight years later, when he saw snakes mating in a similar fashion, he struck them again, and returned to his original shape (in pristinam naturam).

VATICAN MYTHOGRAPHERS	MAP:
Name:  ??? Date:  10th c. CE (?) Works:  Mythographi Vaticani*	REGION  UNKNOWN
BIO:	Timeline:
Little is known about the author or origin of the collection of myths known as the Vatican Mythographers, but the work’s first editor Angelo Mai found the collection on a manuscript dating back to the 10th century CE. This volume is a collection of three different mythographers who have assembled various Greco-Roman myths; although many of these myths are basic summaries in Latin, some of them are either analyzed as allegories or compared to Christian thought.	LATE LATIN (10th c. CE ?)